Apparatus, system, and method for asymmetrical and dynamic routing

ABSTRACT

A regenerator system is provided for dynamic and asymmetric bandwidth capacity adjustment when exchanging data between a first remote network device and a second remote network device. The regenerator includes first and second couplers in communication with the first and second remote network devices, respectively, using a first communication medium that provides multiple communication channels, and at least one redirecting device operable to selectively configure at least one of the channels for either transmission of a signal from the first remote network device to the second remote network device, or transmission of the signal from the second remote network device to the first remote network device.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims the benefit of priorityto co-owned U.S. patent application Ser. No. 14/177,925 titled“APPARATUS, SYSTEM, AND METHOD FOR ASYMMETRICAL AND DYNAMIC ROUTING,”filed on Feb. 11, 2014, the entire contents of which are fullyincorporated by reference herein for all purposes. Application Ser. No.14/177,925 is a continuation-in-part of and claims the benefit ofpriority to co-owned U.S. patent application Ser. No. 13/647,368 titled“APPARATUS, SYSTEM, AND METHOD FOR ASYMMETRICAL AND DYNAMIC ROUTING,”filed on Oct. 8, 2012, now U.S. Pat. No. 8,849,112, the entire contentsof which are fully incorporated by reference herein for all purposes.Application Ser. No. 13/647,368 is a continuation-in-part of and claimsthe benefit of priority to co-owned U.S. patent application Ser. No.13/468,952 titled “APPARATUS, SYSTEM, AND METHOD FOR ASYMMETRICAL ANDDYNAMIC ROUTING,” filed on May 10, 2012, now U.S. Pat. No. 8,285,141,the entire contents of which are fully incorporated by reference hereinfor all purposes. Application Ser. No. 13/468,952 claims priority fromU.S. provisional application No. 61/576,090 titled “APPARATUS, SYSTEM,AND METHOD FOR ASYMMETRICAL AND DYNAMIC ROUTING,” filed on Dec. 15, 2011and to U.S. provisional application No. 61/625,211 titled “APPARATUS,SYSTEM, AND METHOD FOR ASYMMETRICAL AND DYNAMIC ROUTING,” filed on Apr.17, 2012, the entire contents of which are fully incorporated byreference herein for all purposes.

TECHNICAL FIELD

Aspects of the present disclosure relate to communication networks and,in particular, to an apparatus, method, and system for dynamicallyadjusting the bandwidth capacity of two or more network devicesexchanging data in a communication network.

BACKGROUND

The explosive growth of data communication networks, particularly theInternet, presents tremendous opportunities and tremendous challengesfor service providers. One such challenge involves keeping up with thedemand for bandwidth created by new users, new technologies, and newhigh-bandwidth applications. For example, a media on demand serviceprovider often transmits bandwidth demanding multi-media content, suchas video, to a requesting client or end user.

Due to the dynamically changing nature of traffic carried on networks,service providers need the capability to flexibly scale andcost-effectively allocate network resources to provide requiredbandwidth. Currently, to address these dynamically changing bandwidthrequirements, service providers have little choice but to engineer theirnetworks for “worst-case” traffic volumes, which allows them to meetservice commitments but results in under-utilized network resources.Furthermore, when traffic patterns change to an extent that requiresreconfiguration of their networks, service providers must manuallyengineer and provision new connections at both the logical (packet) andphysical and/or optical layers of the network, which can be anexpensive, complex, and time-consuming task.

An incoming request to a multi-media service provider typically includesvery little content as compared to the response which can include alarge amount of content. For example, when requesting a movie in acontent delivery network, the request for the content itself has verylittle data whereas the delivery of the movie may involve gigabytes ofdata. Thus, there is a bandwidth mismatch where communicating therequest to the service provider over the network requires minimalbandwidth, but sending the response with the requested content mayrequire significant bandwidth. Local Area Networks (LAN's), MetropolitanArea Networks (MAN's), and Wide Area Networks (WAN's) along with routingdevices and network switches (such as IP routers, Frame Relay switchesand Asynchronous Transfer Mode switches) interconnected over a TransportNetwork (such as SONET or G.709) are often used to manage such requestsand responses between multiple end users and the service provider. Thesedevices can be implemented by various types of switches and/or networkdevices including, but not limited to asynchronous transfer mode (ATM)switches, frame relay switches, and internet protocol (IP) switches.Unfortunately, due to bandwidth limitations of conventional networkdevices and the disproportional bandwidth requirement between requestsand responses, such network devices often reach their bandwidth capacitybefore responding to all requests and, thus, end users can experiencesignificant latency delays when requesting content, while at the sametime leaving significant bandwidth idle and unused.

Service providers have used Dense Wavelength Division Multiplexing(DWDM) technology to facilitate the transmission large amounts ofcontent. DWDM is a technology that increases the capacity of an opticalfiber by first assigning incoming optical signals to specificwavelengths of light (colors) within a designated band and thencombining or multiplexing multiple optical signals so that they can beamplified as a group and transmitted over a single fiber or pair offibers to increase capacity. Each optical signal can be transmitted at adifferent rate and in a different format. DWDM applications includeultra-high bandwidth long haul as well as ultra-high-bandwidthmetropolitan or inner city-networks, and access networks that are closerto the end user such as SONET, Internet protocol (IP), and asynchronoustransfer mode (ATM) networks.

Conventional DWDM systems use a fixed channel plan that may include, forexample, 40 separate wavelengths (e.g., from 1528 nm to 1560 nm; a 40channel systems uses 100 GHz spaced where an 80 channel system may use50 GHz). Typically, optical signals can be sent across the fiber in thedirection from a network A to a network B or from network B to networkA. Network devices may receive inputs from all directions, but if theend destination is in common for all those inputs, then there can be abuffer fill and overload creating a data bottleneck where data muststream out a fixed capacity, bi-directional transport port. Thus, a“pipe” may be fully utilizing the A to B direction, while the B to Adirection is nearly empty.

It is with these issues in mind, among others, that various aspects ofthe present disclosure were developed.

SUMMARY

According to one aspect, a regenerator system is provided for dynamicand asymmetric bandwidth capacity adjustment when exchanging databetween a first remote network device and a second remote networkdevice. The regenerator includes first and second couplers incommunication with the first and second remote network devices,respectively, using a first communication medium that provides multiplecommunication channels, and at least one redirecting device operable toselectively configure at least one of the channels for eithertransmission of a signal from the first remote network device to thesecond remote network device, or transmission of the signal from thesecond remote network device to the first remote network device.

According to another aspect, a method for adjusting bandwidth capacitybetween a first remote network device and a second remote network deviceincludes selectively configuring, using at least one redirecting device,at least one of a plurality of communication channels of a communicationmedium for either transmission of a signal from the first remote networkdevice to the second remote network device, or transmission of thesignal from the second remote network device to the first remote networkdevice. The regenerator includes a first coupler in communication withthe first remote network device, and a second coupler in communicationwith the second remote network device.

According to yet another aspect, a communication device includes atransmit/receive (T/R) module and multiple first and second opticalredirecting elements. The T/R module includes a receive portion thatreceives a light signal and a transmit portion that transmits the lightsignal. The first optical redirecting elements selectively direct thelight signal between a first port and either the transmit portion or thereceive portion of the T/R module, while the second optical redirectingelements selectively direct the light signal between a second port andeither the transmit portion or the receive portion of the T/R module.

When used in DWDM systems, regenerators are often used to enhance DWDMsignals, such as by re-amplifying, re-shaping, and/or re-synchronizingthe DWDM signals. When used with asymmetric DWDM systems, theseregenerators should be able to re-direct certain wavelengths of DWDMsignals between eastbound and westbound directions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are block diagrams that illustrate a request and responsecommunicated between a client device and a content server using networkdevices.

FIGS. 3A through 3C are block diagrams of communication environmentsaccording to aspects of an asymmetrical and dynamic routing system.

FIG. 3D is a block diagram of multiple network devices connected in amesh configuration according to one aspect of the asymmetrical anddynamic routing system.

FIG. 4 is a block diagram of asymmetrical and dynamic routingapplication according to one aspect of the asymmetrical and dynamicrouting system.

FIG. 5 illustrates a method for enabling dynamic and asymmetricbandwidth capacity adjustment between two or more network devicesaccording to one aspect of the asymmetrical and dynamic routing system.

FIGS. 6A-6C are block diagrams of multiple network devices connected ina mesh configuration according to aspects of the asymmetrical anddynamic routing system.

FIGS. 7A and 7B depict an example embodiment of a light redirectingdevice that may be used with the asymmetrical and dynamic routing systemof FIGS. 3A, 3B, 3C, and/or 3D, respectively.

FIGS. 8A and 8B depict an exemplary regenerator that may be used withthe asymmetrical and dynamic routing system of FIGS. 3A, 3B, 3C, and/or3D, respectively.

DETAILED DESCRIPTION

Aspects of an asymmetrical and dynamic routing system (ADRS) and anetwork device described herein enable the dynamic adjustment of thebandwidth capacity of one or more network devices in communicationwithin a network or between networks. The ADRS includes two or morenetwork devices that are aware of the current total capacity ofbandwidth between two or more network devices. The two or more networkdevices are also configured to monitor their current incoming bandwidthdemands between themselves and subsequently transmit bandwidth requestsand responses to those requests between each other, and/or relaycapacity requests from a different part of the network in a much largernetwork. The network device is configured with additional transmit andreceive ports that can be selectively enabled in response to a bandwidthrequest from other network devices or other devices in the network. Thenetwork devices may also be configured to monitor the bandwidth (e.g.,whether active, idle, near full, or near empty) on other inbound andoutbound ports that may be destined for transmission between the two ormore network devices. The router, in one particular configuration, isconfigured to generate control signals that are sent to optical mirrors,prisms, or other optical redirecting elements can redirect light, todirect data signals from or to the one or more enabled additionaltransmit and receive ports, respectively. Thus, the network device maydynamically adjust the bandwidth by reusing the same wavelength channel(in effect reversing its direction. This is done by enabling oractivating additional idle transmit and/or receive ports in a onedirection (e.g., A to B), while at the same time disabling ordeactivating an additional active receive and/or transmit ports in anopposite direction (e.g., B to A) direction to increase overallasymmetric throughput and thereby reduce short term or long termlatency, bottlenecks, and/or congestion when transmitting high bandwidthdemanding data.

Although asymmetric routing management may enhance the overall capacityof communication links, it may be difficult to implement incommunication links that span long distances. For example, to span longdistances, communication links are provided with regenerators configuredapproximately mid-range between each endpoint. Nevertheless, toimplement asymmetric bandwidth management on links having long spans,the regenerators should also be capable of assisting in asymmetricrouting.

FIG. 1 is a block diagram that depicts data communications betweennetwork devices connected to two different communication networks. Forexample, although the communication networks are different and each maycomprise different hardware (e.g., network devices manufactured bydifferent vendors), both communication networks may utilize the samecommunication protocol. For example, the communication protocol may bean existing communication protocol, which may be an accepted industrystandard protocol or proprietary protocol that has been approved by anynational or international standard authority, such as SONET, which is astandard for connecting fiber-optic transmission systems or proprietaryprotocol developed by vendors for a closed or private system.Alternatively, the communication protocol may be some othercommunication protocol that is used by both communication networks toexchange data. As a result, a requesting device, such as a client device102, and a responding device, such as a content server 104, maintainedby a service provider can exchange data communications between the twocommunication networks.

In operation, the client device 102 sends a request 106 for content,such as streaming video, to a server device by way of a network device A110 via a communication network 112, such as a Local Area Network (LAN).As used herein, a network device is, for example, a router or othersuitable networking equipment such as a switch, gateway, or otherdevices. The network device A 110 may transmit the request 106 to anetwork device B 114 that communicates the request 106 to thedata/content server 104 via another communication network 116, such asanother LAN. A wide area network (WAN) (not shown) may be used toconnect the communication network 112 to the communication network 116.Additionally as shown, the request 106 may be conveyed through aregenerator 118 that applies and otherwise filters the request 106 toimprove its signal quality as seen by the network device B 114.

The server 104 sends a response 108, such as streaming video, to networkdevice B using the communication network 116. Network device B 114transmits the response through the regenerator 118 to network device A110 that communicates the response 108 to client device 102 using thecommunication network 112. Thus, the above network device configurationenables the transmission of information and data between different typesof communication networks.

The request 106 typically includes minimal data relative to the dataincluded in the response 108. In the example of streaming media, therequest 106 may be an HTTP request, such as when a link at a web page isselected from a browser, that includes a network address or other formof location data for the client device 102 from which the request ismade, and includes an identification of the requested streaming mediacontent. In addition to source and destination information, the response108 further includes the requested content in one or more data packets.In the particular example of streaming media, the response will often bea large number of data packets depending on the size of the selectedmedia. To add to the asymmetrical nature of this type of network,multiple client devices 102 may each send a content request 106 to thecontent server 104, the bandwidth required by the network device 114 totransmit the responses 108 each client 102 is typically much greaterthan the bandwidth required by the network device 110 to transmit therequests 106. These bandwidth discrepancies may, in part, result fromcommunication networks 112 and 116 having different data transfer rates.For example, the data rate of communication network 112 may be 10megabytes per second (Mb/s) while the data rate of communication network116 may be 100 Mb/s. As a result, network device B 114 will typicallyreach its bandwidth capacity well before network device A 110 reachesits bandwidth capacity, and it is often the case that network device Asimply will not reach its capacity. Although the response 108 isdescribed as including streaming video content or other forms of mediacontent, it is contemplated that other forms of requested data orcontent can also result in a disparate data amounts between a particularrequest and corresponding response.

FIG. 2 is a block diagram that depicts data communications betweennetwork devices within the same communication network. In this example,a requesting device, such as a client device 202, and a respondingdevice, such as a content server 204, maintained by a service providerexchange data communications via the same communication network. Thesingle communication network facilitates communication between multiplenetwork devices that are each configured to use a communication protocolthat enables dynamic bandwidth adjustment between the multiple networkdevices (e.g., two or more) as described herein. Thus, although one ormore of the multiple network devices may be manufactured by differentvendors, all of the network devices are each configured to communicatewith each other using such a communication protocol and/or pass on tonodes not directly connected.

In this example, the client device sends a request 206 for content, suchas streaming video, to a server hosting or otherwise managing access anddelivery of the content through network 212. In this example, twonetwork devices A and B along with a regenerator 218, among possiblymany others are involved in routing the content between the server andthe client. Thus, the above network device configuration enables thetransmission of information between network devices within the samenetwork or any network device configured as described herein. The ADRSdescribed herein can be implemented in the networks configurationdepicted in FIG. 1, FIG. 2 or any other network configuration thatincludes at least two network devices.

FIGS. 3A and 3B depict exemplary modes of operation of an ADRS accordingto aspects of the present disclosure. As used herein, the term“exemplary” is meant to refer to an example or illustration of onepossible implementation or arrangement of some aspect of the presentdisclosure.

According to one aspect, the ADRS employs a Dense Wavelength DivisionMultiplexing (DWDM) Transmit system that is configured, for example, totransmit eight (8) wavelengths (four reds and four blues, as describedbelow) of any data rate bi-directionally. As described above, DWDM is atechnology that increases the capacity of an optical fiber by firstassigning incoming optical signals to specific wavelengths of light(colors) within a designated band and then combining or multiplexingmultiple optical signals so that they can be amplified as a group andtransmitted over a single fiber or pair of fibers to increase capacity.The multiple wavelengths of light define communication channels thatindependently transmit the multiple optical signals in a communicationmedium, which in a DWDM system, is a fiber optic cable. Each opticalsignal can be at a different rate and in a different format. DWDMapplications include ultra-high bandwidth long haul as well asultra-high-bandwidth metropolitan or inner city-networks, and accessnetworks that are closer to the end user such as G.709, SONET, Internetprotocol (IP), and asynchronous transfer mode (ATM) networks. TypicalDWDM systems International Telecommunications Union (ITU) channel planstoday use 40 wavelengths utilizing a 100 THz channel spacing, or 80λutilizing 50 THz spacing, etc. However, for the purposes ofillustration, the ADRS is described herein as using eight (8)wavelengths λ.

FIG. 3A depicts an exemplary embodiment of an ADRS 300A according to oneaspect of the present disclosure. The ADRS 300 includes a network deviceA 302, a network device B 304, DWDM couplers 306, 308, amplifiers 310,312, and light redirecting components 360-375 and “in the ground” fiber301 (note, this could be bi-directional across one fiber (blues one way,reds the other) or uni-directional across 2 fibers where each fiber hasall 8 wavelengths, one fiber is A to B, the other fiber is B to A),along with all the other “inside” fibers 376-387. The example hereindiscusses implementation of the system using network devices; however,other network devices such as switches may also employ aspects of thedisclosure. The light redirecting components 360-375 may include lightre-directing devices, such as rotatable mirrors, light re-directingdevices and/or, light refracting devices, such as liquid and/or prismbased refracting devices, or other light redirecting devices. The lightredirecting components are configured to receive instructions from theADRS and may be housed in a common unit. Network device A 302 andnetwork device B 304 communicate data signals between each other andeach include an asymmetrical and dynamic routing application (ADRA) 318and a data buffer 320. The data buffer may be a buffer or queue fortemporarily holding data before it is redirected to the proper exitport. As used herein, the terms communicate data or communicating datainclude transmitting and/or receiving data. In a DWDM sense, couplers306, 308 generally refer to passive components, such as connectors thatare incapable of communications without additional active components.

Network device A 302 and network device B 304 also include one or moreprocessors, buffers, and memory and are configured to receive dataand/or communications from, and/or transmit data and/or communicationsto each other. Network device A 302 includes receive ports 321-324,transmit ports 325-328, and idle ports 329-335. Network device B 304includes receive ports 337-340, transmit ports 341-344, and idle ports345-350. Any given network device conforming to aspects of the presentdisclosure may include various possible numbers of ports (or cards) withproportional number of light re-directing components. The ports may beelectronic or optical or a hybrid. The signal is eventually converted tooptical form for the transmission over fiber. In this example, aparticular wavelength (or channel) is assigned to the receive ports321-324 and 337-340 and transmit ports 325-328 and 341-344 such thatthey each can receive and transmit data at a specified wavelength,λ_(x). Different optical channels can carry different data (e.g., voice,data, video, data packets) at different rates. The wavelengths may bedistinguished by different colors. For example, the spectral area may beseparated into numerous distinct color bands which are separatelymanaged. While each of the transmit ports in FIG. 3A are generally hardcoded to transmit a data signal at specified wavelength, they can alsobe selected via executable software or instructions to choose a desiredwavelength. The receive ports can be wide band receive ports such thatthey can receive a data signal at any specified wavelength.

In the bi-directional mode of operation depicted in FIG. 3A, receiveport 321 and transmit port 325 of network device A 302 and receive port337 and transmit port 341 of network device B 304 communicate data at afirst specified wavelength pair λ₁ (which may be red λ₁ from A to B andblue λ₁ from B to A), receive port 322, transmit port 326, receive port338, and transmit port 342 communicate data at a second specifiedwavelength pair λ₂ (which may be red λ₂ A to B and blue λ₂ from B to A),receive port 323, transmit port 327, receive port 339, and transmit port343 communicate data at a third specified wavelength pair λ₃ (which maybe red λ₃ from A to B and blue λ₃ from B to A), and receive port 324,transmit port 328, receive port 340, and transmit port 344 communicatedata at a fourth specified wavelength pair λ₄ (which may be red λ₄ fromA to B and blue λ₄ from B to A). Moreover, in this example, each of thereceive ports 321-324 and 337-340 and transmit ports 325-328 and 341-344each have a bandwidth capacity of bidirectional 10 gigabytes of data persecond (10 Gb/s). Thus, both network device A 302 and network device Bare configured to transmit a total of 40 Gb/s and to receive a total of40 Gb/s in a fully even bidirectional condition. Each port, however, maybe of any data rate, and may mix and match various different data ratesand or protocols. For example ports T_(x1)/R_(x1) could be 10 GigE,while port T_(x2)/R_(x2) could be a 43 Gb/s G.709 OTU3. Either way, if abuffer for a network device is full, capacity requests could be sent outto reallocate wavelength channels to alleviate congestion.

Network device A 302 transmits a plurality of optical data signals (datasignals) 376-379 via fibers 380-383 and light re-directing components360-363 to the DWDM coupler 306. The DWDM coupler 306 then combines ormultiplexes the multiple data signals 376-379 and sends to the amplifier310 via a single fiber 50 so that they can be amplified as a group bythe amplifier 310 across fiber 301 to amplifier 312 which are thentransmitted over another single fiber 60 to coupler 308 for demuxingback into individual channels.

The DWDM coupler 308 receives the combined data signal and demultiplexesthe combined data signal back into individual the multiple data signals376-379. Network device B 304 receives data signals 376, 377, 378, and379 at receive ports 337, 338, 339, and 340, respectively, from the DWDMcoupler 308 via fibers 392-395. In this example, each of the receiveports 337-340 and transmit ports 341-344 also have a bandwidth capacityof 10 gigabytes per second (10 Gb/s) of bidirectional traffic perchannel.

Similarly, network device B 304 transmits a plurality of different datasignals 384-387 via fibers 307, 309, 311, and 313, light re-directingcomponents 368, 370, 372, and 374, and corresponding fibers to the DWDMcoupler 308, then combines or multiplexes the multiple data signals384-387 into a single fiber (e.g., fiber 60) so that they can beamplified as a group by the amplifier 312 and transmitted over the samesingle fiber 301 to coupler 306 for demuxing in various possibleimplementations, a single fiber may be used and data/content istransmitted bidirectionally or a pair of fibers are used withunidirectional traffic on each fiber.

The DWDM coupler 306 receives the combined data signal and demultiplexesthe combined data signal into the multiple data signals 384-387. Networkdevice A 302 receives data signals 384, 385, 386, and 387 at receiveports 321, 322, 323, and 324, respectively, from the DWDM coupler 306via fibers 388-391. In this example, each of the receive ports 321-324and 337-340 and transmit ports 325-328 and 341-344 also have a bandwidthcapacity of 10 Gb/s).

In addition to receive ports 321-324 and transmit ports 325-328, networkdevice A 302 includes an additional set of receive ports 329-331 and anadditional set of transmit ports 333-335. In addition to receive ports337-340 and transmit ports 341-344, network device B 304 includes anadditional set of receive ports 345-347 and an additional set oftransmit ports 348-350. In the mode of operation depicted in FIG. 3A,the additional receive ports 329-331 of network device A 302 are idlealong with transmit ports 348-350 of network device B 304, but can beenabled in response to an authorized bandwidth notification receivedfrom network device B 304. Similarly, the additional receiving ports345-347 of device B 304 and transmit ports 333-335 of network device A302 are idle, but can be enabled in response to an different authorizedbandwidth notification received from network device A 302. Althoughnetwork device A 302 and network device B 304 are each depicted hereinas including three idle receive ports and three idle transmit ports, itis contemplated that in other aspects they may each include fewer ormore active and/or idle receive ports and idle transmit ports. Whennetwork devices A and B (or otherwise) agree to activate or deactivatecertain ports based on overall network wide bandwidth requirements (ormore local bandwidth requirements), the network devices may redirect orallocate certain waves to change direction.

According to one aspect, the data buffer 320 stores data in a buffer orqueue wanting to exit the correct port. The ADRS stores or otherwise hasaccess to threshold port bandwidth data for the corresponding router.The data buffer 320 can be a database or a memory within the networkdevice (e.g., network device A 302 or network device B 304). Thethreshold port bandwidth data identifies a maximum bandwidth capacity ofeach transmit port and receive port for the corresponding router. Forexample, the threshold port bandwidth of network device A 302 indicatesthe maximum bandwidth capacity for each of receive ports 321-324 and329-331 and each of transmit ports 325-328 and 333-335. In this example,and for purposes of illustration, the threshold port bandwidth dataindicates that the maximum bandwidth capacity for each transmit port andreceive port of network device A 302 and network device B 304 is 10Gb/s. It is contemplated that in other aspects the maximum bandwidthcapacity may be greater or less than 10 Gb/s and that each port may havea different maximum bandwidth capacity.

In this example, the light redirecting components 360-375 are opticalreflectors or switches, such as rotatable microelectromechanical system(“MEMS”) micromirrors, that are controllable to redirect orreflect/refract a specific wavelength data signal to a new receive portand/or receive a data signal from a new transmit port. For example,network device A 302 transmits data signals 376-379 via fibers 380-383,respectively, to the DWDM coupler 306 for multiplexing. Network device A302 also receives data signals 384-387 via fibers 388-391, respectively,from the DWDM coupler 306. The light redirecting components 360-363 arepositioned along the fibers 380-383, respectively, between the transmitports 325-328 and the DWDM coupler 306 as well as fibers to receiveports 329-331. The light redirecting components 364-367 are positionedalong the fibers 388-391, respectively, between the receive ports321-324 and the DWDM coupler 306. At least some of the light redirectingcomponents 360-363 are switchably connected to the idle receive ports329-331 and at least some of the light redirecting components 364-367are switchably connected to the idle transmit ports 333-335.

FIG. 3A depicts the transmission of the data signals 384-387 fromtransmit ports 341-344 of network device B 304 to the correspondingreceive ports 321-324 of network device A 302 before network device B304 has reached or nearly reached its bandwidth capacity. After networkdevice B 304 has reached or nearly reached bandwidth capacity, networkdevice B 304 executes the ADRA 318 to enable one or more of its idletransmit ports 348-350 to transmit one or more additional data signalsand to send a bandwidth request to network device A 302. Network deviceA 302 executes the ADRA 318 to determine if excess bandwidth capacity isavailable at network device A 302 and to redirect the one or moreadditional data signals to one or more newly enabled receive ports329-331 at network device A 302 if bandwidth capacity is available. IfNetwork device A 302 accepts the bandwidth request, then thecorresponding wavelength/channel will change direction. For example,light redirecting devices 362 and 373 associated wavelength/channel fortransmitting red λ₃ wavelengths from A to B will toggle at to allow thenewly enabled receive port 329 at network device A 302 and transmit port348 at network device B 304 to become active and make λ₃ now reversed orreused and transmitting from network device B 304 to network device A302).

In operation, the network device A 302 may be used to route or transmitrequests for bandwidth demanding content, such as video. Network deviceB 304 receives the content request and manages the routing of responseswith the requested content back to network device A 302. As describedabove, the request for such content typically requires very littlebandwidth but the response can require significant bandwidth. Althoughnetwork device A 302 can continue to transmit new requests for suchcontent, because of the limited bandwidth network devices can transmitper port, network device B 304 may reach bandwidth capacity, and, thus,responses to new requests will be delayed. This increased latency canadversely affect an end users perception of a particular web servicefrom which the content is being requested.

In another mode of operation of an ADRS 300B depicted in FIG. 3B, theADRA 318 executed on network device B 304 has enabled transmit ports348-349 and has positioned or shifted light redirecting components 373and 375 to transmit additional data signals 396, 397 via fibers 398,399, respectively, to the DWDM coupler 308. The ADRA 318 executed onnetwork device A 302 has enabled receive ports 329-330 and haspositioned or shifted the light redirecting components 362 and 363 todirect the additional data signals 396, 397 at their correspondingwavelengths via fibers 392, 393 to the receive ports 329, 330. As aresult, network device A 302 can receive data signals at six (6) receiveports 321-324, 329, and 330 and can transmit data from two (2) transmitports 325, 326. Network device B 304 can transmit data signals from six(6) transmit ports 341-344, 348, and 349 and can receive data at two (2)receive ports 337, 338. As an example, enabled transmit port 348 ofnetwork device B 304 transmits an additional data signal at the thirdspecified wavelength Red λ₃ and enabled receive port 329 on networkdevice A 302 receives the additional data signal at the third specifiedwavelength Red λ₃. As another example, enabled transmit port 349 ofnetwork device B 304 transmits an additional data signal at the fourthspecified wavelength Red λ₄ and enabled receive port 330 of networkdevice A 302 receives the additional data signal at the fourth specifiedwavelength Red λ₄.

Thus, instead of network device A 302 being configured to transmit amaximum bandwidth of 40 Gb/s to network device B 304, network device A302 is dynamically configured to transmit a maximum bandwidth of 20 Gb/sto network device B 304. Moreover, instead of network device B 304 beingconfigured to transmit a maximum bandwidth of 40 Gb/s to network deviceA 302, network device B 304 is dynamically configured to transmit amaximum bandwidth of 60 Gb/s to network device A 302. By enabling aparticular network device that has reached or is reaching its maximumbandwidth capacity to leverage available and excess bandwidth capacityat a remote router, that particular network device can dynamicallyincrease its throughput to handle large short term or even long termbursts and to reduce latency or lag when transmitting high bandwidthdemanding data in an unpredictable environment.

FIG. 3C depicts another exemplary embodiment of an ADRS 300C. In thisaspect, a plurality of optical transport layers (OTL) components, asindicated by arrow 303, are connected between the network device ports(e.g., transmit and receive ports) and the mirrors. In this aspect, eachOTL component 303 is used to convert a generic wavelength such as 1310nm or 1550 nm signal into a very specific color of light such as 1557.35nm (e.g., see the ITU channel plan for specific wavelengths) and may ormay not modify the signal structure, such as one in which a signal ismodified when encapsulated from an OC192 signal into a G.709 ODU2signal. These OTL components 303 can also be used to manageamplification balancing and wave balancing of data signals beingcommunicated between network device A 302 and network device B 304. Forexample, in this aspect, each of transmit and receive ports of networkdevice A 302 and network device B 304 are configured to transmit datasignals at the same generic wavelength (e.g., 1310 nanometers). The OTLcomponents 303 are used to convert the data signals to a specifiedwavelength (e.g., λ₁, λ₂, λ₃, etc.) for connecting to the DWDM couplers306, 308 at the corresponding wavelength ports.

For purposes of illustration ADRS 300A, ADRS 300B, and ADRS 300C aredescribed herein as comprising two network devices, however it iscontemplated that ADRS 300A, ADRS 300B, and ADRS 300C may include one ormore additional network devices that are each configured to communicatewith each other to dynamically exchange bandwidth capacity and toincrease their throughput to reduce latency or retransmissions due tocongestion when transmitting high bandwidth demanding data. For example,if both network device A 302 and network device B 304 are bothtransmitting data signals at or above a maximum or threshold bandwidthcapacity, they are unable to leverage bandwidth capacity with eachother. In such a circumstance, network device A 302, network device B304, or both can be configured to leverage available and excessbandwidth capacity at one or more other remote network devices. FIG. 3Ddepicts another exemplary embodiment of an ADRS 300D in which more thantwo network devices (e.g., network devices A-F, Y, and Z) are connectedvia a mesh configuration and communicate with each other to leveragebandwidth capacity. Hence, any number of properly configured networkdevices may exchange bandwidth information by way of the protocoldiscussed herein and through the data packet exchanged between networkdevices.

FIG. 3D is an example of a mesh network with a plurality of networkdevices A-Z where the various network devices are configured to performasymmetric and dynamic routing according to aspects of the presentdisclosure. For example, each network device may include an ADRSapplication as discussed herein. Besides ADRS, the network includesconventional intelligence and applications that may identify a failurewithin the network, such as a node failing or being rendered temporarilyinoperative, a cut line, network maintenance, etc. When such an eventoccurs, conventional routing is able to redirect packets around theinoperative network area. The ADRS is also able to redistribute routingcapacity mismatches and bottlenecks that may be instigated by thenetwork problems.

FIG. 4 is a block diagram depicting an exemplary ADRA 318 executing on arouting device 400 and a remote routing device 401. According to oneaspect, the routing device 400 and the remote routing device 401 eachincludes a processing system 402 that includes one or more processors orother processing devices. The processing system 402 executes the ADRA318 to enable one or more idle transmit ports at the routing device andto transmit one or more control signals (e.g., control signals 420 and422) to one or more of the light redirecting components to redirect oneor more data signals being transmitted from the routing device 400 toone or more of the idle receive ports at a remote routing device 401.

According to one aspect, the routing device 400 and the remote routingdevice 401 each includes a computer readable medium (“CRM”) 406configured with the ADRA 318. The ADRA 318 includes instructions ormodules that are executable by the processing system 402 to dynamicallycontrol bandwidth capacity of the routing device 400 and a remoterouting device 401.

The CRM 406 may include volatile media, nonvolatile media, removablemedia, non-removable media, and/or another available medium that can beaccessed by the routing device 400 By way of example and not limitation,the CRM 406 comprises computer storage media and communication media.Computer storage media includes non-transient memory, volatile media,nonvolatile media, removable media, and/or non-removable mediaimplemented in a method or technology for storage of information, suchas computer readable instructions, data structures, program modules, orother data. Communication media may embody computer readableinstructions, data structures, program modules, or other data andinclude an information delivery media or system.

As depicted in FIG. 4, both the routing device 400 and the remoterouting device 401 are configured to execute ADRAs 318. For purposes ofillustration, the execution of the exemplary ADRAs 318 are describedbelow in the context of the remote routing device 401 requestingadditional bandwidth capacity for receiving data signals at the routingdevice 400 that are transmitted from remote routing device 401.

A capacity detection module 408 of the ADRA 318 of the remote routingdevice 401 monitors a current data transmission load or bandwidth at oneor more transmit ports of the remote routing device 401. The capacitydetection module 408 compares the current data transmission load tothreshold port bandwidth data 317 retrieved from the data buffer 320 ofthe remote routing device 401 to determine if a threshold bandwidthcapacity has been reached at one or more transmit ports. For example,according to one aspect, the capacity detection module 408 monitors aqueue or buffer capacity of the remote routing device 401.

The capacity detection module 408 compares the current data transmissionload at each transmit port to a corresponding maximum bandwidth capacityof each transmit port as defined by threshold port bandwidth data 317.In one example, the current data transmission load may correspond to thecapacity of a memory buffer of the network device or tributary bufferassociated with one or more transmit ports. The maximum bandwidthcapacity may correspond to a specified percentage of transmission ortributary buffer capacity (e.g., 90% or 95%). If the remote routingdevice 401 has a current data transmission load that is less than acorresponding maximum bandwidth capacity, the capacity detection module408 continues to monitor the current data transmission load of eachtransmit port or otherwise storing data packets prior to transmission.If one or more of the transmit ports for the remote routing device 401has a current data transmission load that is equal to or exceeds thecorresponding maximum bandwidth capacity for the one or more transmitports, the capacity detection module 408 generates a bandwidth request410 that is transmitted via a communication protocol to the routingdevice 400. According to one aspect, the bandwidth request 410identifies the remote routing device 401 (or source requesting node) andspecifies that it has exceeded its maximum bandwidth capacity. Thecommunication protocol may also require that the bandwidth request 410identify an additional bandwidth required (e.g., bandwidth capacity of20 Gb/s) for accommodating the transmission of additional data signalsfrom the remote routing device 401 to the routing device 400 and/or thespecific wavelength, λ, or optical channel of the additional datasignals.

According to one aspect, the communication protocol uses an in-bandcommunication for communicating the bandwidth request 410, the bandwidthauthorization notification 414, and/or the bandwidth denial notification415 between network device A 302 and network device B 304. Such in-bandcommunication may involve communicating using existing receive andtransmit ports of network device A 302 and network device B 304 that areassociated with a specific wavelength, λ, or optical channel. Forexample, the bandwidth request 410, the bandwidth authorizationnotification 414, and the bandwidth denial notification 415 may becommunicated via transmit port 325 and receive port 321 of networkdevice A 302 and transmit port 341 and receive port 337 network device B304, although no specific port or wavelength is required.

In another aspect, the communication protocol uses out-of-bandcommunication for communicating the bandwidth request 410, the bandwidthauthorization notification 414, and the bandwidth denial notification415 between network device A 302 and network device B 304. Suchout-of-band communication may involve communicating via separatededicated receive and transmit ports that are not associated withtraffic bearing optical channels. For example, the bandwidth request410, the bandwidth authorization notification 414, and the bandwidthdenial notification 415 may be communicated via dedicated protocolcommunication ports (not shown) of network device A 302 and networkdevice B 304. Alternatively, the communication protocol may use anon-data (traffic or sellable service) bearing wavelength betweenexisting ports. For example, traffic bearing channels may use the ITUchannel plan in the range of 1525 nm to 1565 nm, while the OOBcommunication channels may use 1310 nm network device A 302 to networkdevice B 304 and 1425 nm network device B 304 to network device A 302.

In another aspect, in reference to the OTLs 303 described above inreference to FIG. 3C, the communication protocol may also require thatthe bandwidth request 410 identify a specified wavelength for each OTLcomponent 303. Thereafter, the OTL component 303 linked to a particulartransmit port will convert a transmitted data signal having a genericwavelength to a corresponding specified wavelength. The OTL component303 linked to a particular receive port will convert a received datasignal having a specified wavelength to the generic wavelength.

An authorization module 412 of the ADRA 318 of the routing device 400receives the bandwidth request 410 and determines the current datatransmission load of the routing device 400. If the sum of theadditional bandwidth identified in the bandwidth request 410 and thecurrent data transmission load of the routing device 400 is below amaximum data transmission capacity retrieved from the data buffer 320 ofthe routing device 400, the authorization module 412 generates andtransmits a bandwidth authorization notification 414 to remote routingdevice 401. According to another aspect, if the sum of a current datatransmission load of the routing device is equal to or greater than themaximum data transmission capacity retrieved from the data buffer 320,the authorization module 412 generates and transmits a bandwidth denialnotification 415 to remote routing device 401.

A port enabling module 416 of the ADRA 318 of the routing device 400enables one or more idle receive ports at the routing device 400 toaccommodate the desired bandwidth of additional data signals. Forexample, if a bandwidth authorization notification 414 is generated andthe bandwidth request 410 indicates an additional bandwidth of 5 Gb/sand the routing device 400 includes additional receive ports that canaccommodate 10 Gb/s each, the port enabling module 416 enables one ofthe additional receive ports and disables an active transmit port. Asanother example, if the bandwidth request 410 indicates a desiredbandwidth of 15 Gb/s, the port enabling module 416 enables two of theadditional receive ports and disables two of the active transmit ports.It is also contemplated that in other aspects, the port enabling module416 may only enable enough receive ports to accommodate a portion of thedesired bandwidth.

According to another aspect, the port enabling module 416 of the ADRA318 of the routing device 400 enables one or more idle receive ports atthe routing device 400 to accommodate the desired bandwidth ofadditional data signals for one or more corresponding wavelengths inresponse to the generated bandwidth authorization notification 414. Forexample, if a bandwidth authorization notification 414 is generated andthe bandwidth request 410 indicates an additional bandwidth of 5 Gb/s ata specified third wavelength Red λ₃ and the routing device 400 includesan additional receive port (e.g., receive port 329) that can accommodatereceiving 10 Gb/s at the specified third wavelength Red λ₃, the portenabling module 416 enables that particular additional receive port. Inthis example, the port enabling module 416 simultaneously disables acorresponding active transmit port transmitting at the specified thirdwavelength Red λ₃ (e.g., transmit port 327.)

The port enabling module 416 of the ADRA 318 of the remote routingdevice 401 enables one or more idle transmit ports at the remote routingdevice 401 to transmit the additional bandwidth in response to thebandwidth authorization notification 414 received from the routingdevice 400. For example, if the bandwidth authorization notification 414indicates a desired bandwidth of 5 Gb/s has been authorized and routingdevice 400 includes additional receive ports that can accommodate 10Gb/s each, port enabling module 416 of the ADRA 318 enables one of theadditional transmit ports (e.g., transmit port 348) and disables anactive receive port (e.g., received port 339). As another example, ifthe bandwidth authorization notification 414 indicates a desiredbandwidth of 15 Gb/s has been authorized, the port enabling module 416enables two of the additional transmit ports and disables two activereceive ports.

According to another aspect, the port enabling module 416 of the ADRA318 of the remote routing device 401 enables one or more idle transmitports at the remote routing device 401 to transmit the desired bandwidthof additional data signals for one or more corresponding wavelengths inresponse to the generated bandwidth authorization notification 414. Forexample, if a bandwidth authorization notification 414 is generated andthe bandwidth request 410 indicates an additional bandwidth of 5 Gb/s ata specified third wavelength λ₃ and the routing device 400 includes anadditional transmit port (e.g., transmit port 348) that can accommodatetransmitting 10 Gb/s at the specified third wavelength λ₃, the portenabling module 416 enables that particular additional transmit port. Inthis example, the port enabling module 416 simultaneously disables acorresponding active receive port receiving data signals at thespecified third wavelength λ₃ (e.g., receive port 339.)

The control module 418 of the ADRA 318 of the routing device 400generates one or more control signals 420 in response to the generatedbandwidth authorization notification 414. The control module 418transmits the one or more control signals 420 to one or morecorresponding light redirecting components located at the transmit portsof the routing device 400 to reposition or the one or more correspondinglight redirecting components to redirect one or more additional datasignals transmitted from the remote routing device 401 to the newlyenabled received ports at the routing device. According to one aspect, alight redirecting component is responsive to the control signal toreposition by the required amount to redirect or arc the one or moreadditional data signals transmitted from the remote routing device 401toward the newly enabled received ports at the routing device 400.Referring briefly to FIG. 3A as an example, if two additional receiveports 329, 330 have been enabled at the network device A 302 in responseto the bandwidth request signal 410, the control module 414 transmitsthe one or more control signals 420 to corresponding light redirectingcomponents 362, 363 to reposition the light redirecting components andredirect the additional data signals 396, 397 received from the routingB 304 to the two newly enabled receive ports 329, 330 at network deviceA 302.

Similarly, the control module 418 of the ADRA 318 of the remote routingdevice 401 generates one or more control signals 422 in response to thereceived bandwidth authorization notification 414. The control module418 of the remote routing device 401 transmits the one or more controlsignals 422 to one or more corresponding light redirecting componentslocated at the receive ports of the remote routing device 401 toreposition the one or more corresponding light redirecting components toreceive the one or more additional data signals transmitted from theadditional transmit ports enabled at the remote routing device 401. Forexample, each light redirecting component is responsive to a controlsignal to reposition by the required amount to arc or direct the one ormore additional data signals transmitted from the additional transmitports enabled at the remote routing device 401 to the routing device 400via the DWDM couplers 306 and 308.

According to one aspect, the ADRAs 318 use a protocol, such as a LinkAggregation Control Protocol (LACP), to combine or aggregate multipletransmit and receive ports into a logical interface to enable dynamicadjustment of the number of ports included in the aggregated whole oftraffic flow. This allows the transmission of data to be indifferent towhich transmit port of a network device from which it originates sinceall ports are aggregated together to form a single logical port. Inaddition, the communication of the bandwidth request 410, the bandwidthauthorization notification 414, bandwidth denial notification 415, andany other communications between the routing device 400 and remoterouting device 401 may occur in band via dedicated transmit and receiveports. For example, and referring to FIGS. 3A and 3B communications maybe transmitted from the transmit port 341 of remote network device B 304to the receive port 321 of the network device A 302 and communicationsmay be transmitted from the transmit port 325 of network device A 302 tothe receive port 337 of the remote network device B 304.

FIG. 5 is a flow chart that illustrates an exemplary method for enablingdynamic and asymmetric bandwidth capacity adjustment between two or morenetwork devices exchanging data. A bandwidth request is received at arouting device from a remote routing device at 502. As described above,the bandwidth request identifies, in part, the additional bandwidthrequired for accommodating additional data signals to be allocated andsubsequently transmitted from the remote routing device. At 504, an ARDAis executed at the routing device to retrieve threshold port bandwidthdata for the routing device from a data buffer. The ARDA determineswhether the routing device can accommodate the desired bandwidth amountby comparing the sum of a current data transmission load of the routingdevice and the additional bandwidth required to the threshold portbandwidth data at 506. For example, consider network device A 302 iscurrently transmitting below max capacity (e.g., below 50% or 20 G oftotal 40) and network device B desires to allocate 20 gigabytes in the Bto A direction. If A acknowledges or accepts the request, wavelengthchannels Red λ₃ and λ₄ flip directions. If a denial occurs, then networkdevice B may try to leverage available bandwidth at other networkdevices such as C, D or F (see FIG. 3D) and then C, D or F try toallocate new waves to network device A.

Similar to FIG. 3D, FIGS. 6A, 6B, and 6C depict other exemplaryembodiments of an ADRS 600A, 600B, and 600C, respectively, in which morethan two network devices (e.g., network devices A-F), or nodes, areconnected via a mesh configuration and communicate with each other toleverage bandwidth capacity. Hence, any number of properly configurednetwork devices may exchange bandwidth information by way of theprotocol discussed herein and through the data packet exchanged betweennetwork devices. FIGS. 6A, 6B, and 6C are examples of a mesh networkwith a plurality of network devices A-F where the various networkdevices are configured to perform asymmetric and dynamic routingaccording to aspects of the present disclosure. For example, eachnetwork device may include an ADRS application as discussed herein.Besides ADRS, the network includes conventional intelligence andapplications that may identify a failure within the network, such as anode failing or being rendered temporarily inoperative, a cut line,network maintenance, etc. When such an event occurs, conventionalrouting is able to redirect packets around the inoperative network area.The ADRS is also able to redistribute routing capacity mismatches andbottlenecks that may be instigated by the network problems. FIGS. 6A,6B, and 6C also depict upstream network devices G and H, I and J, and Kand L, that are configured to transmit various data traffic to meshnetwork devices E, D, and C, respectively. Likewise, downstream networkdevices M and N are configured to receive various data traffic from meshnetwork device A.

Referring to the example embodiment of FIG. 6A, network device Btransmits data traffic to network device A, and network devices E, D,and C each transmit at least some of this data traffic to network deviceA via network device B. In this example embodiment, the ADRSapplication(s) associated with network devices in the mesh networkperform asymmetric and dynamic routing in accordance with aspects of thepresent disclosure.

In the example embodiment of FIG. 6B, assume that the ADRSapplication(s) were unable to perform asymmetric and dynamic routingbetween network devices A and B. This could be due to one or more of adenial, network failure, maintenance, etc. In such a scenario, the ADRSapplication(s) associated with network devices in the mesh network canattempt to negotiate (or initiate negotiations for) asymmetric anddynamic routing between network devices B and F, and between networkdevices F and A. If enabled, network device B would be dynamicallyreconfigured to asymmetrically transmit data traffic to network device Avia network device F; network device F would be dynamically reconfiguredto asymmetrically receive data traffic from network device B and toasymmetrically transmit data traffic to network device A; and networkdevice A would be dynamically reconfigured to asymmetrically receivedata traffic from network device F, in accordance with aspects of thepresent disclosure.

In the example embodiment of FIG. 6C, assume that the ADRSapplication(s) were unable to perform asymmetric and dynamic routingbetween network devices A and B and/or were unable to perform asymmetricand dynamic routing between network devices B and F, and between networkdevices F and A. This could also be due to one or more of a denial,network failure, maintenance, etc. In such a scenario, the ADRSapplication(s) associated with network devices in the mesh network canattempt to negotiate (or initiate negotiations for) asymmetric anddynamic routing from network devices E, D, and C to network device F(i.e., for at least some of the data traffic associated withtransmissions from each of network devices E, D, and C), and then fromnetwork device F to network device A. If enabled, network devices E, D,and C would be dynamically reconfigured to asymmetrically transmitrespective portions of data traffic to network device F; network deviceF would be dynamically reconfigured to asymmetrically receive respectiveportions of data traffic from network devices E, D, and C, and toasymmetrically transmit data traffic to network device A; and networkdevice A would be dynamically reconfigured to asymmetrically receivedata traffic from network device F, in accordance with aspects of thepresent disclosure.

According to one aspect, if the sum of a current data transmission loadof the routing device is less than a maximum bandwidth capacityspecified by the threshold port bandwidth data at 506, the ARDAgenerates and transmits a bandwidth authorization notification 414 toremote routing device at 508. At 510, the ARDA enables one or more idlereceive ports at the routing device to accommodate the additionalbandwidth in response to the generated bandwidth authorizationnotification.

Another ARDA executing on the remote routing device 401 enables one ormore idle transmit ports at the remote routing device 400 to accommodatethe desired bandwidth in response to the generated bandwidthauthorization notification at 512. At 514, the ADRA generates one ormore control signals in response to the generated bandwidthauthorization notification and transmits the one or more control signalsto adjust one or more corresponding light redirecting components locatedat the transmit ports of the routing device. At 516, the one or morecorresponding light redirecting components are repositioned to redirectone or more additional data signals transmitted from the remote routingdevice 401 to the newly enabled received ports at the routing device400. At 518, the other ADRA generates one or more control signals inresponse to the generated bandwidth authorization notification andtransmits the one or more control signals to adjust one or morecorresponding light redirecting components located at the receive portsof the remote routing device. At 520, the one or more correspondinglight redirecting components are repositioned to redirect one or moreadditional data signals transmitted from the newly enabled transmitports at the remote routing device to the routing device. If the sum ofa current data transmission load of the routing device is equal to orgreater than a maximum bandwidth capacity specified by the thresholdport bandwidth data at 506, the ARDA generates and transmits a bandwidthdenial notification to remote routing device at 522.

Typically, communication links spanning long distances are provided withregenerators for Signal Enhancing typically known as 3R regeneration(i.e., re-amplifying, re-shaping, re-timing) the signals received from atransmitting end point to a quality level sufficient for adequatereception at the receiving end point. Due to this signal degradation,such as any type of dispersion, chromatic dispersion or polarizationmode dispersion, over long distances, 3R or a comparable signalenhancing method, such as Dispersion Compensation Modules or RamanAmplification, electronic dispersion compensation methods, must occur.Nevertheless, these regenerators should intelligently ascertain adirectional path of each channel of the link, and amplify the signal inthat direction for proper operation of the regenerator.

FIGS. 7A and 7B depict various configurations of an exemplary embodimentof a light redirecting device or system 700 that may be used with theADRSs 300A, 300B, 300C, and/or 300D of FIGS. 3A, 3B, 3C, and/or 3D,respectively, or possibly as a stand-alone unit controlled by any othercomparable system. The light redirecting device 700 includes atransmit/receive (T/R) module 701 having a receive portion 702 thatalternatively receives a light signal from either a first port 704 or asecond port 706 and is coupled to a transmit portion 708 of the T/Rmodule that alternatively transmits the light signal to either thesecond port 706 or the first port 704, respectively, using anarrangement of optical redirecting elements 710 a-710 d. That is, eachoptical redirecting element 710 a-710 d is configured to reflect orrefract an incoming light signal in either one of two directions suchthat its respective light redirecting device 700 may direct the lightsignal in a direction suitable for asymmetrical routing.

The light redirecting device 700 may perform 3R regeneration, or othersignal enhancing or cleansing method on a light signal in eitherdirection, namely from the first port 704 to the second port 706 asshown in FIG. 7A, or from the second port 706 to the first port 704 asshown in FIG. 7B. The directional amplification of the light signal iscontrolled by the optical directing elements 710 a-710 d. Thus, bycontrolling the operation of the optical directing elements 710 a-710 d,the redirecting device 700 may perform 3R regeneration, or other signalenhancing or cleansing technique in any desired direction. As shown,active light signal paths are indicated by arrows and inactive (e.g.,not currently used) light signal paths are indicated by dashed lines.

FIG. 7A (eastbound) depicts an arrangement of the optical directingelements 710 a-710 d in which the light signal is directed rightwardfrom port 704 to port 706. In this arrangement, optical directingelement 710 a reflects or refracts the light signal received from port704 to optical directing element 710 b, which in turn reflects orrefracts the light signal to the receive portion 702 of the T/R module701. Additionally, optical directing element 710 c reflects or refractsthe light signal emanating from the transmit portion 708 to opticaldirecting element 710 d, which in turn reflects or refracts the lightsignal to port 706.

In contrast, FIG. 7B (westbound) depicts an alternative arrangement ofthe optical directing elements 710 a-710 d in which the light signal isdirected leftward from port 706 to port 704. In this arrangement,optical directing element 710 d reflects or refracts the light signalreceived from port 706 to optical directing element 710 b, which in turnreflects or refracts the light signal to the receive portion 702 of theT/R module 701. Additionally, optical directing element 710 c reflectsor refracts the light signal emanating from the transmit portion 708 tooptical directing element 710 a, which in turn reflects or refracts thelight signal to port 704.

Thus, the light redirecting device 700 may alternatively transmit thelight signal in opposing directions between the first port 704 and thesecond port 706 according to the configuration of the opticalredirecting elements 710 a-710 d. As shown, a single T/R module 701 isused to alternatively transmit light from the first port 704 to thesecond port 706, or transmit light from the second port 706 to the firstport 704. This functionality differs from that of the optical transportlayer (OTL) component 303 shown in FIG. 3C in which two T/R modules areused. The two T/R modules include a tributary side T/R module (typically1310 nm) and a network side T/R module (typically DWDM wavelengthspecific, such as 1557.52 nm). The OTL component 303 is fullybidirectional, whereas light redirecting device 700 is meant to take aDWDM wavelength and may change directions (i.e. from eastbound towestbound). Whereas the OTL component 303 alternatively transmits lightsignals bidirectionally in opposing directions by alternatively turningon/off either T/R module ports, the light redirecting device 700alternatively transmits a single signal in opposing directions bymanipulating the light signal path through a number of opticalredirecting elements 710 a-710 d.

FIG. 8A depicts an example regenerator 800 according to the teachings ofthe present disclosure. Embodiments of the regenerator 800 may be usedwith the ADRSs 300A, 300B, 300C, and/or 300D of FIGS. 3A, 3B, 3C, and/or3D, respectively. For example, the regenerator 800 may be implemented toimprove light signals (re-construct, re-structure, re-shape, re-time,re-amplify), such as light signals of an ADRS, when used between tworouters of a communication network that are separated by a relativelylong distance due to a natural degradation in the signal quality overthose distances.

The regenerator 800 includes multiple light redirecting devices 700described above with reference to FIGS. 7A and 7B that may be used forregenerating multiple light signals of the ADRS. Nevertheless, it shouldbe understood that the regenerator 800 may be implemented with anysuitable light redirecting device that selectively directs lightsignals. Additionally, the light redirecting device 700 may beimplemented on or within any system in which the selective direction oflight signals is needed or desired. For example, the regenerator 800 iscoupled to a first coupler 802 that may be optically coupled to router A302 (See FIGS. 3A, 3B, and 3C) using a first optical cable 804 (e.g.,fiber 301 of FIGS. 3A-3C) and a second coupler 806 that may be opticallycoupled to router B 304 using a second optical cable 808 (e.g., fiber301 of FIGS. 3A-3C).

The regenerator 800 also includes an optical redirecting devicecontroller application (ORDCA) 812 that controls the configuration ofthe optical redirecting devices 700. In general, the ORDCA 812 controlsthe optical directing elements 710 a-710 d of each redirecting device700 to selectively direct their respective light signals in eitherdirection through the regenerator 800 for synchronizing the direction ofchannel through the regenerator to the directions using by the routers.The ORDCA 812 is discussed in detail below with respect to FIG. 8B.

In one embodiment, the regenerator 800 may be used to perform 3Rregeneration or a comparable signal enhancing technique for each channelof the fiber cable between router A 302 and router B 304. For example,when router A 302 and router B 304 are spaced a relatively long distance(e.g., a distance great enough to degrade the signal) from one another,attenuation of signals transmitted between router A 302 and router B 304as well as noise introduced in the cable may reduce signal quality atits termination point. Thus, the regenerator 800 may be configured at asuitable location between router A 302 and router B 304 or at multiplelocations between A and B to clean (e.g., clean, re-construct,re-configure, re-shape, re-time, and/or amplify) signals and/or filternoise from the signals such that signal quality may be maintained at asufficiently high level and sent on to the next location. Additionally,multiple regenerators 800 may be coupled between router A 302 and routerB 304 in which the transmit/receive modules each include an amplifierand/or filter to clean and/or filter light signals of the ADRS.

In one embodiment, the optical redirecting devices 700 provide fullgrooming of the channels of the fiber optic cable. That is, all, some,or none of the channels may be transmitted in any one direction basedupon the configuration of the optical redirecting devices 700. Forexample, an optical redirecting device 700 may be provided for eachchannel of the fiber cable such that all, some or none of the signalstransmitted through the channels may be directed from router A 302 torouter B 304, or that all some or none of the channels may be directedfrom router B 304 to router A 302. In other embodiments, only one or aspecified number of redirecting devices 700 may be implemented such thata specified subset of channels may be selectively directed in opposingdirections between router A 302 and router B 304.

FIG. 8B is an exemplary block diagram depicting an exemplary ORDCA 812executed on the regenerator 800. According to one aspect, theregenerator 800 includes a processing system 814 that includes one ormore processors or other processing devices. The processing system 814executes the ORDCA 812 to control the configuration of the opticalredirecting devices 700.

According to one aspect, the regenerator 800 includes a computerreadable medium (“CRM”) 816 that stores the ORDCA 812 and a data source824. The ORDCA 812 includes instructions or modules that are executableby the processing system 814 to dynamically control bandwidth capacitybetween router A 302 and router B 304 by manipulating the configurationof the optical redirecting devices 700. The data source 824 may be abuffer or queue for temporarily holding data before it is redirected tothe proper exit port.

The CRM 816 may include volatile media, nonvolatile media, removablemedia, non-removable media, and/or another available medium that can beaccessed by the regenerator 800. By way of example and not limitation,the CRM 816 comprises computer storage media and communication media.Computer storage media includes non-transient memory, volatile media,nonvolatile media, removable media, and/or non-removable mediaimplemented in a method or technology for storage of information, suchas computer readable instructions, data structures, program modules, orother data. Communication media may embody computer readableinstructions, data structures, program modules, or other data andinclude an information delivery media or system.

In the specific examples illustrated and discussed herein, acommunication module 818 of the ORDCA 812 communicates with the ADRA 318of either router A 302 and/or router B 304 to receive instructions forconfiguring the redirecting devices 700, and for reporting performancecharacteristics of the regenerator 800 and/or signals passed through theregenerator 800. For example, when the ADRA 318 manipulates thedirectional configuration of any channel of the fiber cable, it willalso instruct the regenerator 800 at one or many sites along a route tomanipulate the directional configuration of the redirecting devices 700associated with that channel such that the path of the communicationsignal of that channel between router A 302 and router B 304 ismaintained.

In FIG. 8B, a redirecting device control module 820 of the ORDCA 812controls the configuration of each redirecting device 700 configured inthe regenerator 800. Moreover, the ORDCA 812 synchronizes the directionof each channel of the link with each channel as configured in therouters. For example, the redirecting device control module 820 controlsthe optical redirecting elements 710 a-710 d to reflect and/or refractthe light signal in accordance with a desired direction of the path ofthe associated channel.

The redirecting device control module 700 may also detect a faultcondition of any channel and report the fault condition to the ADRA 318via the communication module 818. For example, a light directing device710 b configured on a particular redirecting device 700 may have failedsuch that it is no longer capable of reflecting or refracting its lightsignal from light directing device 710 d to the receive portion 702 ofthe T/R module 701. In this case, the receive portion 702 of the T/Rmodule 701 will then generate a loss of signal (LOS) alarm when itsrespective redirecting device 700 is arranged to direct its light signalfrom port 706 to port 704. The redirecting device control module 820processes the LOS alarm and transmits information associated with theLOS alarm to the ADRA 318 through the communication module 818.

An amplification/filtering control module 822 controls any cleaningand/or filtering to be applied each redirecting device 700. The cleaningand/or filtering applied to each redirecting device 700 may be appliedaccording to any suitable criteria. In one embodiment, cleaning and/orfiltering to each redirecting device 700 may be applied as a closed-loop(e.g., sense and response) system in which the module 822 receivesmeasurements associated with the signal quality from sensors thatmeasure one or more characteristics the light signal, and adjusts thecleaning and/or filtering applied to the light signal according to thereceived measurements. One or more of the sensors may be configuredwithin each redirecting device 700, or one or more of the sensors may beconfigured at either or both routers in which the module 822 receivesthe measurements provided by the ADRA 318 and received through thecommunication module 822.

In another embodiment, the module 822 may apply cleaning and/orfiltering to each redirecting device 700 according to genericinformation known about the ADRS. For example, it may be known that thephysical communication line between each router is approximately 35miles in length. Given this known length, the module 822 may apply acertain amount of cleaning and/or filtering based upon this known lengthto condition the light signal for suitable reception at its receivedpoint.

It should be appreciated that the modules described herein are providedonly as an example of a computing device that may execute the ORDCA 812according to the teachings of the present invention, and that othercomputing devices may have the same modules, different modules,additional modules, or fewer modules than those described herein. Forexample, one or more modules as described in FIG. 8B may be combinedinto a single module. As another example, certain modules describedherein may be encoded and executed on other computing devices, such asthe computing device configured in router A 302 or router B 304.Further, one or more or all of the modules may be stored and executed bythe ORDCA 812 while data and instructions are transmitted to and fromrouter A 302 and/or router B 304 to execute their functions.

Although the regenerator 800 has been described herein as being adaptedfor use with a fiber optic cable link with multiple channels usingdiffering wavelengths of light, it should be understood that theregenerator 800 may be used with any communication medium that providesmultiple channels in which the direction of signals of any one of thesechannels may be individually selected relative to the other channels.

The description above includes example systems, methods, techniques,instruction sequences, and/or computer program products that embodytechniques of the present disclosure. However, it is understood that thedescribed disclosure may be practiced without these specific details.

In the present disclosure, the methods disclosed may be implemented assets of instructions or software readable by a device. Further, it isunderstood that the specific order or hierarchy of steps in the methodsdisclosed are instances of example approaches. Based upon designpreferences, it is understood that the specific order or hierarchy ofsteps in the method can be rearranged while remaining within thedisclosed subject matter. The accompanying method claims presentelements of the various steps in a sample order, and are not necessarilymeant to be limited to the specific order or hierarchy presented.

The described disclosure may be provided as a computer program product,or software, that may include a machine-readable medium having storedthereon instructions, which may be used to program a computer system (orother electronic devices) to perform a process according to the presentdisclosure. A machine-readable medium includes any mechanism for storinginformation in a form (e.g., software, processing application) readableby a machine (e.g., a computer). The machine-readable medium mayinclude, but is not limited to, magnetic storage medium (e.g., floppydiskette), optical storage medium (e.g., CD-ROM); magneto-opticalstorage medium, read only memory (ROM); random access memory (RAM);erasable programmable memory (e.g., EPROM and EEPROM); flash memory; orother types of medium suitable for storing electronic instructions.

It is believed that the present disclosure and many of its attendantadvantages will be understood by the foregoing description, and it willbe apparent that various changes may be made in the form, construction,and arrangement of the components without departing from the disclosedsubject matter or without sacrificing all of its material advantages.The form described is merely explanatory, and it is the intention of thefollowing claims to encompass and include such changes.

While the present disclosure has been described with reference tovarious embodiments, it will be understood that these embodiments areillustrative and that the scope of the disclosure is not limited tothem. Many variations, modifications, additions, and improvements arepossible. More generally, embodiments in accordance with the presentdisclosure have been described in the context of particularimplementations. Functionality may be separated or combined in blocksdifferently in various embodiments of the disclosure or described withdifferent terminology. These and other variations, modifications,additions, and improvements may fall within the scope of the disclosureas defined in the claims that follow.

What is claimed is:
 1. A regenerator system enabled for dynamic andasymmetric bandwidth capacity adjustment when exchanging data between afirst remote network device and a second remote network device, theregenerator system comprising: a first coupler in communication with thefirst remote network device using a first communication medium operableto provide a plurality of communication channels; a second coupler incommunication with the second remote network device using a secondcommunication medium operable to provide the plurality of communicationchannels; and a computing device comprising at least one memory forstorage of an optical redirecting device controller application executedon at least one processor to: control one or more redirecting devicesfor selectively configuring at least one of the plurality ofcommunication channels for, in response to a first request from at leastone of the first and second network devices, transmission of a signalfrom the first remote network device to the second remote networkdevice, and, in response to a second request from at least one of thefirst and second remote network devices, reversing the at least one ofthe channels for transmission of the signal from the second remotenetwork device to the first remote network device; receive measurementsassociated with a quality of the signal; based on the receivedmeasurements, adjust at least one of cleaning and filtering applied tothe signal.
 2. The regenerator system of claim 1, wherein the first andsecond communication medium comprises first and second fiber opticcables, and the one or more redirecting devices comprises at least onelight redirecting device.
 3. The regenerator system of claim 2, whereinthe first and second remote network devices comprise dense wavelengthdivision multiplexing (DWDM) devices, and the plurality of communicationchannels configured to transmit a plurality of light signals havingdiffering wavelengths relative to one another.
 4. The regenerator systemof claim 1, wherein the one or more redirecting devices comprises twotransmit/receive modules for each channel.
 5. The regenerator system ofclaim 1, wherein the processor is further configured to control the oneor more redirecting devices to: selectively couple the first coupler toa receive portion of a T/R module and the second coupler to a transmitportion of the T/R module; and selectively couple the second coupler toa receive portion of the T/R module and the first coupler to a transmitportion of the T/R module.
 6. The regenerator system of claim 1, whereina transmit/receive module of the one or more redirecting devicescomprises performs at least one of re-shaping the signal, re-amplifyingthe signal, re-synchronizing the signal, re-configuring the signal, andre-constructing the signal.
 7. The regenerator system of claim 1,wherein the one or more redirecting devices comprise are equal inquantity to the number of the plurality of communication channels.